In conventional print systems, a print job, to be executed by a print request from a client, is stored into a print server. The print server manages the order of print jobs, and monitors a printer as an output destination. If print-output is possible in the printer, the print server outputs the print jobs in print order to the printer, and clears the print jobs.
Further, in recent print systems, to reduce load on a network and a print server, a client transmits only a print request for execution of print job to the print server. The actual print job is stored in the client. When the print server receives the print request, it manages the order of print jobs, and if it is determined that print-output is possible in the printer, the print server sends a print permission to the client. The client directly outputs the print job to the printer and clears the print job.
In this manner, generally, one of a server that manages the order of print jobs and a client that issues a print request holds (spools) a print image as the actual object of print job. In a case where the server holds the print image, (in case of server spool), even when the client is down, the print job is ensured, and the printer status can be intensively managed. On the other hand, in a case where the client holds the print image (in case of client spool), as the print image is transmitted only from the client to the printer, the frequency of occurrence of LAN busy status is low.
In the above system, the object to be spooled in the server or client is a print image of the print job, i.e., only print data actually outputted to the printer. Further, when the print data has been outputted to the printer, the spool data in the server or client is deleted (cleared), and reuse of the data or the like is not considered.
Further, the client can obtain a list of print jobs spooled in the server and display job information (document names, owners names, print request times), however, as the job information of the print jobs spooled in the server include a small amount of information, it is impossible to know actual print-outputs to be obtained from the print jobs.
As described above, in the system where one of the server and the client has an image spooler has the following problems.
In a system where a server holds print data (print image), the print-data transmission routes are (I) client-server and (II) server-printer, i.e., the data is transmitted always via the server. This increases load on the LAN and easily causes a busy status. Further, as the server spools print data from a plurality of clients, it requires a large capacity memory. This increases load on the server and costs.
On the other hand, in a system where a client holds print data, the client cannot refer to a print job to be executed by a print request from another client. Otherwise, even if the client can obtain a list of print jobs to be executed by print requests from the clients to the server, the client can not obtain actual print-outputs of jobs regarding which the client did not issue print requests, only from the document names and the like. Further, when a client spooling a print job is down, the print job is not ensured.